Today, a user may receive services from a variety of service providers, such as broadcast television networks, cable television networks, digital satellite systems, and internet service providers. Most television receivers are capable of receiving unscrambled information or programs directly from broadcast and cable networks. Cable networks providing scrambled (or encrypted) programs usually require a separate stand alone set-top box to descramble the program. Similarly, digital satellite systems usually provide scrambled programs that also require the use of a set-top box (STB). These set-top boxes may utilize a removable smart card which contains the keys necessary for recovering the descrambling keys.
Conditional access (CA) systems allow users access to certain programs offered by broadcasters, cable providers, internet service providers and digital satellite providers. In the case of cable and satellite providers, such programs (e.g., Home Box Office (HBO), Pay Per View channels, etc.) often have additional costs above the ‘basic’ cable or satellite costs. Typically, authorization for such programming is updated on a monthly basis depending upon whether the user has paid for such programming for the particular month. In the case of PPV or VOD, authorizations are typically done on a per request basis (i.e., authorization is given when the channel is requested).
The current method for updating a user's authorization to receive Pay TV programs is commonly referred to as ‘homing.’ In a homing process, a digital device such as a set-top box (STB), digital videocassette recorder (DVCR) or digital television (DTV) includes software which ‘homes’ or tunes to a particular channel in order to receive the authorization for the programming. Typically, this homing is done when the user is not operating the digital device (e.g., when the user is not watching television).
Typically, the authorization is accomplished through Entitlement Management Messages (EMMs) which are sent from the service provider (e.g., cable company) to the user's digital device. For example, if the service provider receives payment for HBO for the month of July, the service provider will send an EMM authorizing HBO to the particular user's digital device (e.g., set-top box) in the month of June. Typically, a smart card within the digital device receives the EMM and processes it to authorize HBO for the month of July. If the EMM is not received in June, the first time the user attempts to view HBO in July they will be informed (preferably by a message appearing on the television screen) that they are not authorized or subscribed to that channel.
In another exemplary EMM scheme, a smart card within the digital device has a set amount of money or credit stored thereon which is debited each time a channel is authorized for a particular month. Periodically, the service provider sends an EMM which restores the full credit value to the smart card. However, if the EMM is not received, the smart card may not have enough credit to authorize a particular channel (e.g., HBO) for a particular month. This scheme avoids the problem of updating all subscriber smart cards every month, but smart cards still need to be updated on some periodic basis, thus requiring homing by the digital device.
In most cases, EMMs are sent to the subscribers utilizing a ‘carousel’ system. Carousel systems repeatedly send EMMs to maximize the ability of the digital devices to receive the data. Each subscriber of the system has a separate EMM which authorizes his or her particular programs and services. Further, even if two or more users of the system subscribe to the same service package, their EMMs are different. Thus, if there are 10,000 subscribers of the system, the carousel must deliver 10,000 EMMs in a given cycle.
Because Pay TV systems can have very large subscriber bases, the carousel can take quite a while to send a particular EMM. For example, a given metropolitan regional service area (e.g., Indianapolis, Ind.) may possess the following characteristics:
Approximate Number of People1.5 millionServedApproximate Number of Homes500,000Approximate Number of Users187,500(30% of homes @ 1.25 STB per home)EMM Carousel Data1.5*108 bits (800 bits per user)Carousel Time25 minutes (1 Megabit/second)Thus, without using homing, a subscriber must watch HBO (or some other channel on which an EMM may be received) for at least 25 minutes in one month to be authorized to receive HBO for the next month.
To avoid this result, most modern digital devices (e.g., STBs) perform homing when the devices are not in use. However, the problem here is that the digital device must be continually powered up (even if not “on” or in operating mode) in order to receive the EMMs. Thus, a user must keep his digital device plugged in at all times, thereby increasing power demands and electricity costs.
For example, a digital device that is homing uses roughly 10-15 Watts of standby power. At an approximate rate of 10 Watts per hour for 20 hours a day, and assuming power cost of 8 cents per kilowatt hour (KWh), homing costs the average subscriber approximately 1.6 cents per day, or $5.84 per year. This amount becomes even more significant when multiplied by the number of digital devices homing in a particular service area.
Additional problems exist with present homing techniques. For example, some televisions are virtually never turned off (e.g., televisions in a bar or hotel lobby), and thus will never have time to home. Additionally, smart cards must be left in the digital devices in order for the homing process to work. Certain subscribers may want to remove their smart card when they are not using the television to prevent children from purchasing programs or watching particular channels. Further, one conditional access system could attempt to ‘block’ another conditional access system by consuming all the available homing time. For example, if a given user subscribes to four (4) different conditional access systems, four different service providers will be attempting to send four different EMMs, and thus the digital device may have to choose between which one to receive (or ‘home’ to) first. Finally, digital devices with multiple slots for receiving smart cards must arbitrate between conditional access systems when they are in the ‘off’ mode. Therefore, it is clear that conventional conditional access systems consume too much time and energy for homing.
Thus, there is presently a need for a digital device that allows a user to have a specified unconfirmed viewing time in which to allow the digital device to perform homing.